With the evolving of semiconductor technologies, semiconductor chips/dies are becoming increasingly smaller. In the meantime, more functions need to be integrated into the semiconductor dies. Accordingly, the semiconductor dies need to have increasingly greater numbers of I/O pads packed into smaller areas, and the density of the I/O pads rises over time. As a result, the packaging of the device dies becomes more difficult, which adversely affects the yield of the packaging.
To solve this problem, process have been developed to encapsulate a device die in an encapsulating material such as molding compound, and forming redistribution lines to connect to the surface pads of the device die. The redistribution lines span to a greater area than the device die, and allow for more I/O pads to be formed without the need to increase the area of the device die.